Forward-propagate assumptions/assertions (if possible) to strengthen the analysis

[danmatichuk]

Generally the only information that is propagated forwards is equivalence domains and value domains. Neither of these are suitable for representing relational properties beyond simple equality (e.g. r1 (original) == r2 (patched)).

Often these relational properties are introduced in the form of equivalence conditions or assertions, but they are only available in exactly the CFAR where they are introduced. To carry this information forward, it needs to be asserted later and then propagated backwards in order to be used.

To recover this information in some cases, we can attempt to forward-propagate any conditions for a CFAR using the existing equivalence domain rescoping heuristics.

This is a simple change in lieu of a more invasive change to the equivalence/value domains in order to support more kinds of relations.